Conventionally, a grasping hand with a multi-joint portion drive mechanism has been used for grasping of particular components in a limited working environment of a factory interior primarily as a hand of industrial robots, and has been under discussions and contrivance in view of higher precision, higher speed, and the like for specialized operations. In recent years, in contrast to this, there has been brisk development pertaining to robot introduction in household aid and work aid, care aid for aged or physically challenged, and the like in home, hospitals, and the like, giving rise to a desire for a grasping hand which satisfies such conditions as grasping of various and diverse objects, which could not be implemented by industrial robots, and safety to persons who use the grasping hand and which is capable of fulfilling flexible operations. For grasping of diverse objects, there has been known a robot hand described in Japanese Patent No. 3245095. This robot hand has five fingers consisting of a 4-degree-of-freedom thumb having one 4-joint-portion and four 3-degree-of-freedom fingers each having a 4-joint-portion, where miniature servomotors are contained at joint portions other than a finger-tip first joint portion, respectively, to drive the joint portions.
However, this robot hand, involving large numbers of component parts, requiring assembly and being high-priced, is still limited to research use at the present time.
With regard to a grasping hand capable of fulfilling flexible operations, a pneumatic actuator, which is one constituent element, is known as described in Japanese Patent No. 3226219. This actuator is so designed that a plurality of partition walls are provided in a cylindrical elastic member to define pressure chambers, wherein each of the pressure chambers is to be pressurized to flex the elastic member. This actuator is combined in a plurality to form a grasping hand, thus being enabled to grasp objects.
However, since there is provided no constituent element equivalent to a human bone, there would arise an issue in that it may become hard for the actuator to continue grasping an object depending on its configuration and weight. Also, in order to drive each actuator, there would arise a need for drive tubes of a number corresponding to a number of internal pressure chambers of cylindrical elastic members. In this case, the number of tubes would increase, causing a load more than a flexural operation force of the actuators to be involved depending on rigidity of the tubes, thereby posing a possibility that the actuators might no longer sufficiently flex.
With regard to these already reported grasping hands, there has been disclosed no grasping hand which comprises pneumatic pressure as a drive source and which includes a laminated-type pneumatic tube formation member, a planar-type joint-portion flexural deformation member and a bone member having a joint portion according to the present invention.
For introduction of robots for performing various kinds of aid into human living space, there is a need for a multi-joint portion drive mechanism for fulfilling a grasping hand that serves as a main part for aid operation. Also, the grasping hand provided with the multi-joint portion drive mechanism is required to have a grasping performance for grasping various and diverse objects and to be safe, simple in structure, and implementable with low cost.
An object of the present invention is to provide a laminated-type multi-joint portion drive mechanism, as well as a manufacturing method therefor, and further to provide a grasping hand and a robot arm provided with the laminated-type multi-joint portion drive mechanism as well as a robot provided with the grasping hand and the robot arm each of which solves the foregoing issues and each of which is capable of implementing a grasping hand having a grasping performance for various and diverse objects, and which is safe and simple in terms of structure and implementable with low cost.